The challenge, according to information from researchers at Los Alamos National Laboratory (LANL) in New Mexico: storage. While hydrogen packs a high energy content per unit mass when compared to petroleum, it also packs a low energy content per unit volume, making it hard to get enough of the element on board a vehicle to power it a reasonable distance.

image via Toyota

So, scientists have been working with chemical compounds that store hydrogen. The star compound in these efforts: ammonia borane. Ammonia borane has a hydrogen storage capacity of almost 20%, a figure LANL says is good enough such that, with “appropriate engineering” it can be used to power a vehicle further than 300 miles. The problem is that once the hydrogen is released from the compound, there’s been no efficient way to charge it back up.

The good news is that LANL researchers, in conjunction with University of Alabama researchers, have figured out a way to “recharge” the spent fuel tanks. The process requires a sealed pressure tank and uses hydrazine and liquid ammonia at 40 degrees Celsius to recharge the tank with usable fuel, so the process has to be done at a special facility, but a tank exchange system could eliminate that inconvenience. With this method, one some day might be able to change out a fuel tank in much the same way that people exchange propane tanks for their BBQs and RVs.

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“scientists havenu2019t managed to develop a 100% hydrogen fuel cell vehicle” nn-What about the one in the picture, or the Honda FCX-Clarity or the Hyundai Tucson FC, or the Mercedes Benz F-Cell… These and many more are fuel cell vehicles that run solely on hydrogennnMost of these have fuel tanks with a water volume of 200 litres or less, to state:n”would require a tank larger than some cars” n-how many cars occupy a volume of less than 0.2 cubic meters?nnand:n”While hydrogen packs a big punch per its mass (itu2019s light) it packs a relatively low punch per its weight (itu2019s bulky)”nmeasuring energy density by weight or mass is the same thing and exceptionally high in either case, its stored weight however is low, around 3% of a full hydrogen cylinder is the gas with the rest being the vessel. you would need to replace “weight” with “volume” for this statement to be true.nnnThis is a very misleading article and should be withdrawn or re-edited.